Why is crosslinking of BCRs important for B cell activation?
I. Crosslinking of BCRs allows for antigen presenting cells to bind to B cells
II. Crosslinking of BCRs must occur before the BCRs can bind to their matching antigen
III. Crosslinking of BCRs properly positions signaling molecules to carry the signal deeper into the cytoplasm
A) I only
B) III only
C) I and II
D) II and III
E) I, II, and III

Question

Why is crosslinking of BCRs important for B cell activation? 
I. Crosslinking of BCRs allows for antigen presenting cells to bind to B cells
II. Crosslinking of BCRs must occur before the BCRs can bind to their matching antigen
III. Crosslinking of BCRs properly positions signaling molecules to carry the signal deeper into the cytoplasm
A) I only
B) III only
C) I and II
D) II and III
E) I, II, and III

Quizplus · Accepted Answer

The crosslinking of BCRs properly positions scr kinases to phosphorylate downstream targets and carry the signal into the cell, eventually to the nucleus to alter transcription. The crosslinking occurs after antigen binding, not before, and does not facilitate binding of antigen presenting cells.

Why Is Crosslinking of BCRs Important for B Cell Activation